The word upkeep does not technically exist as a verb in the English lexicon. The verb closest verb in meaning to the action described by the noun upkeep, meaning the act of maintaining in good condition, is maintain.

What is the plural of upkeep?

upkeep (usually uncountable, plural upkeeps) Maintenance; the act or effort of keeping something in good and working condition.

Can you use upkeep as a verb?

Upkeep can be a noun or a verb.